1. Field of the Invention
The present invention relates to a semiconductor wafer cleaning apparatus. More particularly, the present invention relates to a single type of semiconductor wafer cleaning apparatus and to a method of cleaning a semiconductor wafer using the same.
2. Description of the Related Art
In general, semiconductor wafer cleaning apparatuses include batch and single types. In the batch type of semiconductor wafer cleaning apparatus, several semiconductor wafers are cleaned simultaneously. Although the production efficiency of the batch type of semiconductor cleaning apparatus is high, the cleaning efficacy is low. On the contrary, in the single type of semiconductor wafer cleaning apparatus, the production efficiency is low, and the cleaning efficacy is high. When manufacturing highly-integrated semiconductor devices it is important that the semiconductor wafer be very clean at several stages in the process. Thus, the single type of semiconductor wafer cleaning apparatus is preferred over the batch type.
Also, ozone (O3) has been used to increase the cleaning efficacy of conventional semiconductor wafer cleaning apparatuses. Semiconductor wafer cleaning apparatuses using ozone (O3) include a normal bath type of semiconductor wafer cleaning apparatus that uses a solution containing ozone (O3), a spray type of semiconductor wafer cleaning apparatus that uses ozone (O3) in a gaseous state, and a vapor type of semiconductor wafer cleaning apparatus that uses a mixture of vapor and ozone (O3).
In the bath type of semiconductor wafer cleaning apparatus, the cleaning solution is saturated when the concentration of the ozone (O3) is in the range of 10-20 ppm at room temperature. Thus, it is difficult to use ozone (O3) in high concentrations and at high temperatures in a bath type of semiconductor wafer cleaning apparatus. In the spray type semiconductor wafer cleaning apparatus, a semiconductor wafer is rotated while de-ionized water is sprayed to form a layer of water thereon. Subsequently, the ozone (O3) concentration in the layer of water is increased by spraying ozone (O3) into the chamber, whereby the semiconductor wafer is cleaned. However, in the spray type semiconductor wafer cleaning apparatus, the thickness of the water layer as a means of diffusing the ozone (O3) is proportional to the rate of rotation of the semiconductor wafer. Accordingly, the spray nozzle must be complex so that the ozone (O3) can be sprayed uniformly over the entire surface of the semiconductor wafer. In the vapor type of semiconductor wafer cleaning apparatus, ozone (O3) and vapor are mixed, and the mixture is sprayed onto a semiconductor wafer. In this way, the ozone (O3) is diffuses into vapor molecules attached to the semiconductor wafer, whereby the ozone (O3) concentration can be increased by tens of thousands of ppm. However, in the vapor type of semiconductor wafer cleaning apparatus, the ozone (O3) is used under high pressure in a sealed chamber, and vapor adheres to sides of the chamber.